Air diffusing systems are designed to redirect air which is supplied from a duct in the ceiling of the enclosed environment. Prior solutions are directed to screen made from fabric material. By contrast, the inventive method is directed air diffuser made of molded tight mesh.
In general, it has been known that air diffusers redirect air as it flows into a room from a ceiling mounted supply duct. Without a diffuser, the air provided by the duct will flow straight down into the room. This can cause undesirable air drafts or turbulence within the room.
The prior art diffusers solve this and other problems by redirecting and diffusing the air as it enters the room. To accomplish this goal, the exit "face" of a typical prior art diffuser has a group of angled vanes or louvers. In addition, directional devices may be found inside the duct above or behind the outlet portion of the system.
Prior art diffusers that utilize angled vanes include those set forth in U.S. Pat. No. 3,948,155, issued Apr. 6, 1976 (Warren R. Hedrick), U.S. Pat. No. 4,266,470, issued May 12, 1981 (Schroeder et al.), U.S. Pat. No. 4,366,748, issued Jan. 4, 1983 (Wilson et al.), U.S. Pat. No. 5,054,379, issued Oct. 8, 1991 (Franc Sodec), U.S. Pat. No. 5,192,348, issued Mar. 9, 1993 (Craig S. Ludwig), and U.S. Pat. No. 5,454,756, issued Oct. 3, 1995 (Craig S. Ludwig).
Fabric sheets have been used in diffuser systems to filter dust and other particulate matter from the air passing into the room. U.S. Pat. No. 4,603,618, issued Aug. 5, 1986 (Charles W. Soltis), discloses a clean room ventilation system having a fabric sheet fixed above a perforated ceiling grid. The fabric sheet filters the air and provides a uniform laminar flow of air into the room. The fabric sheet and perforated grid extend across the entire ceiling, and air flows from the ceiling straight down into the room.
The prior art air diffusers have many problems. They often accumulate dust, which tends to build up around the angled vanes. In addition, the prior art air-handling systems tend to be noisy.
Fabrics have also been used to absorb sound. U.S. Pat. No. 4,152,474, issued May 1, 1979 (Cook, deceased et al.), discloses an acoustic absorber which comprises a substrate having a plurality of openings. An organic polymer coating covers the substrate and partially fills the openings in the substrate.
Prior to the present invention a method has been discovered for diffusing air flowing from an air supply duct. The method included using an open-weave fabric sheet for changing the air flow from a vertical to a lateral direction and velocity after exit from the sheet, mounting the fabric sheet in a holding frame, and installing the frame-sheet assembly at the exit portion of the duct.
However, there are drawbacks in the use of fabric based air diffusing systems. First, the surface of the fabric screen is manufactured in batch lots such that the flexibility is curtailed as size, shape, density, and aperture shape, dimension, and number. Moreover, there are difficulties in the biaxial stretching by tensioning the fabric within the holding frame. It is also difficult to permanently color or stain such a fabric diffusing screen in the small lots.
It is the object of this invention to provide an air diffusing system which overcomes the disadvantages or complications of the fabric-based prior art by balancing air flow and air passage, through the diffusing screen, thus controlling air supply and distribution into an enclosed environment along the ceiling so as to reduce or eliminate direct downward air drafts or turbulence.
Another object of this invention is directed to a significant reduction in noise usually associated with the passage of air through a diffusion system, particularly as produced by the angled vane type diffusers.